A Buyers Guide to LED Bulbs

Doshwaster

Interesting stuff. I have been thinking off replacing my GU10 halogen spotlights in the house (16 x 35W in total) as they must be costing me a fortune in electricity and constantly need replacing but the initial cost and the sheer range of different bulbs available has been putting me off.

I think the way forward is to try a few different bulbs to make sure they fit the fittings and the colours are fine before shelling out on replacing them all.

jimmy_81

This is very timely; we'll be redoing our bathroom in January and I've been considering LED downlights... So thanks elstimpo for a very useful post! :T

One thing I don't understand, though - do you need special lampholders for LED - or can you just use standard GU10 inset spotlight holders with LED bulbs?

The LED downlights I've been looking at appear to be integrated units i.e. the LED lamp is built into the holder. Presumably they're relying on the long LED lifetime and if anything was to go amiss, you replace the whole thing? As they seem to run approx £40 each, that's a slightly scary idea!

My preference would be to go with simple lampholders & LED bulbs... But maybe I'm missing something?

If anyone can shed any light on this, I'd greatly appreciate it...

Buzby

Existing GU10 lamp holders are fine - but watch out for the profile, as some will protrude (ie not fit flush to the ceiling).

Integrating lamp & holder would be disastrous - but it may simply be a well designed complementary design.

Doshwaster

I've just picked up a 2 pack of GU10 led lights from Homebase (http://www.homebase.co.uk/webapp/wcs/stores/servlet/ProductDisplay?langId=110&storeId=10151&partNumber=100730) and they fit my existing fittings perfectly so I'll be going back tomorrow to get some more.

malc_b

A point on your payback calculation. You have ignored the 40W the incandescent etc. gives as home heating. Most lighting is during the winter when you heat as well so although the electric cost 13p you save about 50% of that in gas etc. so payback isn't 1 year but 2.

JohnB47

malc_b wrote: »

A point on your payback calculation. You have ignored the 40W the incandescent etc. gives as home heating. Most lighting is during the winter when you heat as well so although the electric cost 13p you save about 50% of that in gas etc. so payback isn't 1 year but 2.

It seems unlikely that 50% of a bulbs power consumption would be given off as heat, although i do agree that halogens get very hot. Have you any evidence for that?

Edit: see next post.

JohnB47

I correct myself! Its worse than that. As this website shows, most of the energy goes towards heat, apart from led technology.

http://www.lightson.ca/comparing-light-bulb-efficiencies-or-the-money-you-waste-on-heat

almillar

I've just picked up a 2 pack of GU10 led lights from Homebase (http://www.homebase.co.uk/webapp/wcs...tNumber=100730) and they fit my existing fittings perfectly so I'll be going back tomorrow to get some more.

250 lumens - equivalent to 50W? I don't think so! Keep the receipt!

malc_b

JohnB47 wrote: »

It seems unlikely that 50% of a bulbs power consumption would be given off as heat, although i do agree that halogens get very hot. Have you any evidence for that?

50% is the equivalent cost you'd pay for gas (i.e. in round terms gas is half the price of electric). Just about 100% of the power you put into a bulb ends up as heat eventually (except for light that shines out of a window). Light falling on wall, curtains, etc. will end up as heat, plus of course there is the heat given off the lamp itself. So in round terms 100% of the electrical energy ends up as heat (i.e. no light escapes), which saves 50% of electric cost in central heating gas.

Biggles

malc_b wrote: »

50% is the equivalent cost you'd pay for gas (i.e. in round terms gas is half the price of electric). Just about 100% of the power you put into a bulb ends up as heat eventually (except for light that shines out of a window). Light falling on wall, curtains, etc. will end up as heat, plus of course there is the heat given off the lamp itself. So in round terms 100% of the electrical energy ends up as heat (i.e. no light escapes), which saves 50% of electric cost in central heating gas.

So, using that logic, an LED gives out as much heat as an incandescent?